1. Field of the Invention
This application relates generally to the deposition of silicon-containing materials in semiconductor and microelectromechanical systems (MEMS) processing. More particularly, this application relates to the production of activated Si precursors and to the polymerization of those precursors to form Si-containing films.
2. Description of the Related Art
In recent years, microelectronics manufacturers have been shrinking transistor size in integrated circuits (IC's) to improve device performance. This has resulted in increased speed and device density. The speed of an electrical signal in an IC is primarily governed by two components—the switching time of an individual transistor, known as transistor gate delay, and the signal propagation time between transistors, known as RC delay. In past years, the RC delay was negligible in comparison with the signal propagation delay. For modern sub-micron technology, however, the RC delay has become the dominant factor.
To reduce RC delay, semiconductor IC manufacturers have sought to replace the SiO2 materials used in the interlevel dielectrics (ILD's) of IC's with materials having lower dielectric constants. For example, in some cases performance gains were achieved by replacing SiO2 (k=3.9) with fluorinated silica glass (k˜3.5). In addition, a variety of low-k porous polymeric materials have been developed for use in IC's. See, e.g., U.S. Patent Publication No. 2003/0100691 A1. However, the integration of polymeric porous materials into semiconductor device manufacturing flows has been problematic, see R. Wilson, “Session Spotlights Challenges of Low-k Materials,” EE Times, July 2002. As a result, the semiconductor industry has postponed three times the transition to low-k ILD's, see “Technology Readiness Overview—Low-k Interlevel Dielectrics Technology—Brief description of low-k technology,” NASA Electronic Parts and Packaging Program, August 2003. Thus, there is a long-felt need for new low-k materials and methods for making them, suitable for use in semiconductor manufacturing.